1. Field of the Invention
The present invention relates generally to sleds, sleighs, and related devices for travel over ice and snow, and more particularly to a small single occupant sled having two fixed rearward runners and a single steerable front runner. The present three runner sled incorporates various improvements over sleds of the prior art, including an adjustable front suspension, novel brake means, and means for carrying the device on the back of a person on foot.
2. Description of Related Art
Sleds and related vehicles have been developed in many cultures throughout the world, wherever climatological conditions provide for ice and snow. Generally speaking, sleds have not evolved appreciably over the years, and can be divided into a relatively few classes based upon their runner configurations. The present invention relates more particularly to sleds having multiple runners with at least one steerable runner, as opposed to toboggans, dual fixed runner sleds, and the like.
Most sleds known in the past are relatively simple devices, having no suspension and relatively crude (if any) steering. Such devices are generally intended purely for recreation, and are generally operated by one or more occupants (generally children) in relatively short runs down a reasonably gentle slope. In such conditions, such relatively primitive sled configurations are reasonably safe. However, the poor suspension, steering, and brakes (if any) provided with such sleds, can easily prove to be a hazard if an occupant or user attempts a slope which leads to somewhat more speed than he or she is used to, or more speed than the relatively primitive sled configuration is equipped to handle.
Accordingly, a need will be seen for a single occupant three runner sled which incorporates various features which provide additional safety margins for persons using the present sled. The present three runner sled incorporates a front suspension which may be adjusted as desired for the weight and seating position of the occupant, as well as the ambient snow or ice conditions (rough, smooth, etc.). Independent brakes are also provided behind each of the rear runners, with the brake shoes being interchangeable as desired for different conditions. A xe2x80x9cdead man""s,xe2x80x9d or emergency, brake is also automatically actuated in the event the occupant falls from the sled. The kneeling position provided for the occupant of the present sled is somewhat like that used with personal watercraft, and provides a relatively low center of gravity while still allowing the occupant to shift his or her weight readily for better control.
A discussion of the related art of which the present inventors are aware, and the differences and distinctions between that art and the present invention, is provided below.
U.S. Pat. No. 3,682,495 issued on Aug. 8, 1972 to Kourosh Zaimi, titled xe2x80x9cSnow Bike,xe2x80x9d describes a three runner device somewhat resembling the classic two runner ski-bob, in that a bicycle type seat is provided on the longitudinal member extending forwardly from the single non-steerable rear runner. However, the Zaimi device includes two steerable front runners, with the directions of the front runners being independently controllable relative to one another. Each front runner has an independent brake, with each separately steerable handlebar having a brake lever thereon for the brake on that side. The seating position does not provide the versatility of the present sled""s seating position, and the two independently steerable front runners and single rear runner are essentially reversed from the configuration of the present sled.
U.S. Pat. No. 3,833,234 issued on Sep. 3, 1974 to Hermann Schreiber, titled xe2x80x9cVehicle, In Particular For Training In The Coordination Of Several Controls,xe2x80x9d describes a three runner sled having a single steerable front runner and two fixed rearward runners. No specific seating arrangement is disclosed, but it is apparent that the operator""s feet must be deployed forwardly, as the directional steering is configured to simulate the forwardly disposed rudder pedals of a conventionally controlled aircraft. Other controls cause the Schreiber sled to bank by tilting the sled relative to the two rearward runners, unlike the present sled.
U.S. Pat. No. 3,858,896 issued on Jan. 7, 1975 to Jean-Yves Evequoz, titled xe2x80x9cSki-Bob,xe2x80x9d describes a three runner sled having a single steerable front runner and two closely spaced rear runners. While the conventional ski-bob is equipped with only two runners in tandem, the Evequoz sled is closely related, as the two rear runners have only enough clearance therebetween to provide for independent operation of their separate suspensions. They are so closely spaced that no real lateral stability is provided, with the operator being required to balance laterally using his or her feet. In any event, no adjustability is disclosed for the front suspension, as provided by the present sled, and the seating arrangement of the Evequoz sled is completely different, due to the need to position the operator""s feet laterally from the sled for stability.
U.S. Pat. No. 3,900,208 issued on Aug. 19, 1975 to Stig Gunnar Hjelmquist, titled xe2x80x9cSleds,xe2x80x9d describes a three runner sled having a single steerable front runner and two directionally fixed rear runners. However, the Hjelmquist sled has no suspension whatsoever and a single hand operated brake affixed to the front runner, rather than the two rearwardly disposed and independently controllable brakes of the present sled. Moreover, the seating position is unlike that of the present sled, with the Hjelmquist sled having a generally rearwardly disposed seat and lateral runners extending forwardly of the seat for placement of the operator""s feet. Hjelmquist also uses a steering wheel, rather than handle bars, for directional control of his sled.
U.S. Pat. No. 4,063,746 issued on Dec. 20, 1977 to Odd Hansen, titled xe2x80x9cSledge,xe2x80x9d describes a three runner sled having a single steerable front runner and two directionally fixed rear runners. The two rear runners are linked together at their forward ends by a crossmember which passes in front of the steering column of the device; no suspension means is disclosed for the front runner or ski. The seating position is completely different than that provided by the present sled, with the operator""s feet positioned forwardly of the seat in order to operate the forwardly disposed brake spurs which extend through the forward portions of the two laterally spaced rear runners, more or less laterally in line with the steering wheel.
U.S. Pat. No. 4,101,142 issued on Jul. 18, 1978 to Richard W. Turner, titled xe2x80x9cSnow Sled Turning Mechanism,xe2x80x9d describes a three runner sled having a single steerable front runner steered by handlebars. The Turner sled includes a relatively wide body portion for the occupant(s) and braking means extending from each of the non-steerable rear runners, with the brakes being independently selectively actuated by corresponding levers on the handlebars. No specific seating position is shown or described by Turner, but it is apparent that the rider""s feet are not positioned rearwardly, as Turner does not provide any rearwardly disposed foot rests in his sled. Moreover, while Turner provides a suspension spring for the front runner, he makes no disclosure of any means of adjusting the front suspension in any way, whereas the present sled includes front suspension adjustment means.
U.S. Pat. No. 4,141,566 issued on Feb. 27, 1979 to David M Benes et al., titled xe2x80x9cWheelchair Supporting Sled,xe2x80x9d describes a sled having a single steerable front runner with four laterally spaced rearward runners, the two outermost runners being provided for increased lateral stability. Steering and braking are controlled respectively by a handlebar and brake handgrips on the handlebar. No seating position is provided in the Benes et al. sled. Rather, a series of clamps is provided to secure a wheelchair frame removably to the sled structure, with the wheelchair providing the required seating for the operator. No rearwardly disposed footrests are provided (other than for an optional second occupant, who has no seating, standing upon the rearward ends of two of the main runners), as a person confined to a wheelchair would obviously not be able to rest his/her feet in such rests.
U.S. Pat. No. 5,335,925 issued on Aug. 9, 1994 to Murray Dolson, titled xe2x80x9cSnow Sled,xe2x80x9d describes a three runner sled having a single steerable front runner and two directionally fixed rear runners. The front runner may include suspension means. The frame and seating are adjustably secured to the main runners, which are connected by flexible members which pass through inverted U-shaped tubes beneath the seat. Thus, the operator may rock the seat laterally to maintain a level seating position when traversing a slope laterally. No braking means is disclosed by Dolson, and the footrest position is relatively far forward, adjacent the forward portion of the seat, rather than being rearwardly disposed as in the present sled invention.
U.S. Pat. No. 5,518,080 issued on May 21, 1996 to Liano Pertile, titled xe2x80x9cSnow Vehicle,xe2x80x9d describes a three runner sled with a pair of front runners and a single rear runner. The Pertile sled may be powered or unpowered. A relatively complex mechanism steers the front runners, with other means provided for tilting or banking the sled relative to the front runners. The frame is articulated between the front runners and single rear runner, with the seat having a spring suspension relative to the frame. No specific suspension is provided for the front runners, however. The only footrest areas provided appear to be on the rearward portions of the front runners, due to the narrow single rear runner.
U.S. Pat. No. D-252,505 issued on Jul. 31, 1979 to Gennady G. Derkach et al., titled xe2x80x9cSnow Sled,xe2x80x9d illustrates a design for a three runner sled having a configuration much like that of the Hjelmquist ""208 U.S. Utility Patent discussed further above. No braking means is apparent in the Derkach et al. design, and the design uses handlebars rather than the steering wheel of Hjelmquist, but otherwise the points raised in the discussion of the sled of the Hjelmquist ""208 U.S. Utility Patent, are seen to apply here as well.
Finally, Canadian Patent Publication No. 1,037,529 issued on Aug. 29, 1978 to Odd Hansen, titled xe2x80x9cSledge,xe2x80x9d is based upon the same Norwegian parent application as the ""746 U.S. patent to the same inventor, discussed further above. Accordingly, the same points of distinction between the sled of the ""746 U.S. patent and the present invention noted above, are seen to apply here as well.
None of the above inventions and patents, either singly or in combination, is seen to describe the instant invention as claimed.
The present invention comprises a relatively small and light weight sled having a single steerable front runner and a pair of laterally disposed, directionally fixed rear runners. The present sled is adapted for use by a single rider or operator, in the manner of xe2x80x9cski-bobxe2x80x9d type personal ski devices or sleds. However, the operator or rider position is more akin to that used with many smaller personal watercraft (e. g., Jet-Ski(copyright)), rather than conventional sleds of the prior art.
The present three runner sled includes an adjustable front suspension for the steerable front runner, and a rearwardly disposed footrest atop each of the rearwardly disposed directionally fixed runners. A relatively narrow and elongate seat is provided along the raised central framework, from which the fixed runners depend to each side. Brakes are provided to the rear of the footrests, with the brakes being selectively actuated by independently controllable hand grips on the steering handlebars. The brake shoes or xe2x80x9cpawsxe2x80x9d may be interchanged as desired for different conditions (snow, ice, etc.), and an automatic xe2x80x9cdead man""sxe2x80x9d brake is also provided to stop the sled in the event the rider falls from the sled. The present sled further includes means for carrying the device on the back of a person on foot, if desired.
Accordingly, it is a principal object of the invention to provide a three runner sled having a single steerable front runner and two laterally spaced, directionally fixed rear runners, providing various safety and convenience features over conventional sleds of the related art.
It is another object of the invention to provide a three runner sled including adjustable front suspension means and selectively controllable independent braking means disposed rearwardly from each of the rearward runners, and an emergency brake activated by inadvertent operator dismount from the sled.
It is a further object of the invention to provide a three runner sled including a relatively narrow central seat with rearwardly disposed footrests for the operator, positioning the operator optimally for leaning laterally for better control of the sled.
Still another object of the invention is to provide a three runner sled including means for carrying the device conveniently upon the back of a person on foot, for transporting the sled to and from an area of use.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.